Both civilian and military aircraft sometimes employ various electronic systems which are fundamental for communication activities, navigation and warning (surveillance), such as sensors, antennas and radar. For example, optical sensors on the aircraft may allow the pilot to identify visually specific geographical and/or terrain attributes in low visibility environments. The electronic systems, depending on the purpose and dimensions of the equipments, are allocated in the aircraft belly, disposed externally or in compartments having a specifically designed fairing forming a protuberance on the smooth lines of the aircraft.
The inconveniences of such protuberances reside in the fact of an increase in the aerodynamic drag, which influences directly the fuel consumption, range and speed limit of the aircraft and also promotes in-flight turbulence. Further, generally speaking, the sensors typically present a spherical shape in which surface is located one or more lenses having a circular format in plan. Once such sensors are exposed to airflow, they become susceptible to vibrations due to the detachment of aerodynamic vortexes. It is also known that useful life of the sensors is related to the intensity of the vibrations which are proportional to dynamic pressure and exposure of the sensors to the airflow.
Due the cost of such equipment and its strategic importance during reconnaissance missions, the installation in aircraft is usually made in a way to allow the equipment to be retractable thereby making it possible to expose the equipment only when necessary for use and to retract the equipment when it is not in use.
Among the different types of known retractable systems, the most common are those that execute vertical movement as taught by U.S. Pat. Nos. 3,982,250, 3,656,164, 4,593,288, 5,969,686 and 5,918,834. However, such a vertical movement in turn implicates an interface with the pressurized area of the aircraft or requires a significant protuberance on the exterior side of the fuselage thereby leading to the disadvantages already mentioned.
Other retractable pantographic systems are also known, but the operation kinematics is seen as a complex procedure mainly due to interaction with the articulated doors, which are defined by heavy mechanisms having relatively large physical dimensions responsible for maintaining the compartment closed. One disadvantage of such a system is due to the fact that the relatively large door surfaces generate disturbances in the air flow when they are extended during the flight. As a result, the entire assemblage becomes subject to strong vibrations which in turn causes mechanical wearing of the parts composing the system and damage to the sensors over time.
It is noticed that the previous proposals in this art are replete with disadvantages that induce relatively high costs of operation and maintenance. Thus, one aspect of the present invention is to provide a new technique that minimizes such disadvantages, as well as providing for a smooth curvilinear surface that reduces turbulence and drag in use.
One objective of the present invention is therefore to present a retractable system for aeronautical sensors which is capable of guaranteeing the physical integrity of the equipment.
Another objective of the present invention is to present a retractable system for aeronautical sensors that makes possible exposition and retraction of the electronic equipment starting from a short angular movement.
Another objective of the present invention is to present a retractable system for aeronautical sensors that uses just a single door built in a fairing of the aircraft.
Another objective of the present invention is to present a retractable system for aeronautical sensors which doesn't require exaggerating protuberances on the aircraft fuselage or wing, thus allowing a minimal space for accommodation inside the aircraft.